Using pigments within a polymer film in toothpaste is a technology used in markets outside of the US. In the US, however, only dye is allowed in oral care products. A significant problem of using water soluble dye is that the dye is water soluble and leaches out of a film almost immediately upon addition to a formulation that contains water, causing an unacceptable color bleeding.
There is a need for dentifrices, such as toothpastes, comprising films which contain a dye, such that the dye does not appreciably leach out from the polymer film until use.